Wild salmon have been put under increased pressure by more than 20 incidents of mass escapes of fish from Scottish farms since the start of 2019, experts have warned.
Around 73,000 farmed salmon, each weighing an average of 1.9kg, broke free from their open-net cage near Colonsay during Storm Brendan last month.
Experts estimate the number of escapees is around double how many wild Atlantic salmon return to their home rivers on the west coast of Scotland.
Farmed salmon pose a risk to their wild counterparts as it can lead to inbreeding and the spread of disease.
The site belongs to Mowi Scotland, which discovered a tear in the cage during an inspection after the stormy weather.
The Atlantic Salmon Trust has now called for the aquaculture industry to update the standards for the construction and maintenance of cages.
A spokeswoman said: “While a single escape of over 70,000 farmed salmon is an unfortunate accident, many more are occurring.
“Since the start of 2019, over 20 incidents of farmed salmon escapes have been reported to the Scottish Government.
“The combined impact of all these farmed salmon escaping into the wild is not fully known but do represent a significant risk to the vital recovery of our remaining west coast salmon stocks.”
More than 120,000 salmon have got out of Mowi Scotland fish farms on the west coast since October.
The Norwegian government believes farmed salmon escapes are the biggest threat to its wild salmon.